Encyclopedia Astronautica
Pegasus XL/HAPS


American air-launched orbital launch vehicle. Five stage version consisting of 1 x L-1011 + 1 x Pegasus XL stage 1 + 1 x Orion 50XL + 1 x Orion 38 + 1 x HAPS

LEO Payload: 350 kg (770 lb).

Status: Active.
Gross mass: 23,000 kg (50,000 lb).
Payload: 350 kg (770 lb).
Height: 17.40 m (57.00 ft).
Diameter: 1.28 m (4.19 ft).
Thrust: 726.00 kN (163,211 lbf).
Apogee: 4,000 km (2,400 mi).
First Launch: 1997.12.23.
Last Launch: 2005.04.15.
Number: 6 .

More... - Chronology...


Associated Countries
Associated Spacecraft
  • Orbcomm American communications technology satellite. 31 launches, 1991.07.17 (Orbcomm-X) to 2008.06.19 (Orbcomm FM36). Orbcomm was a commercial venture to provide global messaging services using a constellation of 26 low-Earth orbiting satellites. More...
  • Microstar American communications technology satellite. 22 launches, 1995.04.03 (Orbcomm F1) to 2008.10.19 (Formosat 3F). Small satellite bus, specially designed for multiple launch by Pegasus or Taurus family launch vehicles. More...
  • TERRIERS American earth ionosphere satellite. One launch, 1999.05.18. More...
  • DART American rendezvous technology satellite. One launch, 2005.04.15. Autonomous Rendezvous Technology mission, planned to guide itself to within a few meters of a US satellite. More...

See also
  • Pegasus Privately-funded, air-launched winged light satellite launcher. More...

Associated Manufacturers and Agencies
  • OSC American manufacturer of rockets, spacecraft, and rocket engines. Orbital Sciences Corporation, USA. More...

Associated Programs
  • Orbcomm Orbcomm was a commercial venture to provide global messaging services using a constellation of 26 low-Earth orbiting satellites. More...

Associated Launch Sites
  • Point Arguello WADZ Air-launched rocket drop zone known to have been used for 28 launches from 1990 to 2007, reaching up to 4539 kilometers altitude. More...
  • Wallops Island DZ Air-launched rocket drop zone known to have been used for 6 launches from 1996 to 1999, reaching up to 834 kilometers altitude. More...

Associated Stages
  • L-1011 Subsonic rocket launch aircraft. Loaded/empty mass 156,000/109,629 kg. Thrust 561.90 kN. Specific impulse 9900 seconds. Lockheed airliner swept wing. Release conditions: Belly-mounted, 36,800 kg, 17.1 m length x 7.9 m span at 925 kph at 11,890 m altitude More...
  • Orion 50SXL Solid propellant rocket stage. Loaded/empty mass 17,934/2,886 kg. Thrust 589.01 kN. Vacuum specific impulse 293 seconds. More...
  • Pegasus XL-2 Solid propellant rocket stage. Loaded/empty mass 4,331/416 kg. Thrust 153.50 kN. Vacuum specific impulse 290 seconds. More...
  • Pegasus-3 Solid propellant rocket stage. Loaded/empty mass 985/203 kg. Thrust 34.57 kN. Vacuum specific impulse 293 seconds. More...

Pegasus XL/HAPS Chronology


1997 December 23 - . 19:11 GMT - . Launch Site: Wallops Island DZ. Launch Pad: 37.0 N x 72.0 W. Launch Platform: L-1011. LV Family: Pegasus. Launch Vehicle: Pegasus XL/HAPS. LV Configuration: Pegasus XL/HAPS F19.
  • Orbcomm A1 - . Payload: Orbcomm s/n FM5. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Microstar. USAF Sat Cat: 25112 . COSPAR: 1997-084A. Apogee: 823 km (511 mi). Perigee: 812 km (504 mi). Inclination: 45.0300 deg. Period: 101.26 min. Summary: Plane A. Ascending node 297.7 degrees..
  • Orbcomm A8 - . Payload: Orbcomm s/n FM12. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Microstar. USAF Sat Cat: 25119 . COSPAR: 1997-084H. Apogee: 823 km (511 mi). Perigee: 812 km (504 mi). Inclination: 45.0200 deg. Period: 101.26 min. Summary: Plane A. Ascending node 301.2 degrees..
  • Orbcomm A5 - . Payload: Orbcomm s/n FM9. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Microstar. USAF Sat Cat: 25116 . COSPAR: 1997-084E. Apogee: 822 km (510 mi). Perigee: 814 km (505 mi). Inclination: 45.0200 deg. Period: 101.26 min. Summary: Plane A. Ascending node 301 degrees..
  • Orbcomm A6 - . Payload: Orbcomm s/n FM10. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Microstar. USAF Sat Cat: 25117 . COSPAR: 1997-084F. Apogee: 823 km (511 mi). Perigee: 812 km (504 mi). Inclination: 45.0200 deg. Period: 101.26 min. Summary: Plane A. Ascending node 301.2 degrees..
  • Orbcomm A7 - . Payload: Orbcomm s/n FM11. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Microstar. USAF Sat Cat: 25118 . COSPAR: 1997-084G. Apogee: 823 km (511 mi). Perigee: 813 km (505 mi). Inclination: 45.0200 deg. Period: 101.26 min. Summary: Plane A. Ascending node 301.2 degrees..
  • Orbcomm A3 - . Payload: Orbcomm s/n FM7. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Microstar. USAF Sat Cat: 25114 . COSPAR: 1997-084C. Apogee: 822 km (510 mi). Perigee: 813 km (505 mi). Inclination: 45.0300 deg. Period: 101.26 min. Summary: Plane A. Ascending node 301 degrees..
  • Orbcomm A2 - . Payload: Orbcomm s/n FM6. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Microstar. USAF Sat Cat: 25113 . COSPAR: 1997-084B. Apogee: 822 km (510 mi). Perigee: 813 km (505 mi). Inclination: 45.0300 deg. Period: 101.26 min. Summary: Plane A. Ascending node 300.7 degrees..
  • Orbcomm A4 - . Payload: Orbcomm s/n FM8. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Microstar. USAF Sat Cat: 25115 . COSPAR: 1997-084D. Apogee: 823 km (511 mi). Perigee: 813 km (505 mi). Inclination: 45.0200 deg. Period: 101.26 min. Summary: Plane A. Ascending node 300.5 degrees..

1998 August 2 - . 16:24 GMT - . Launch Site: Wallops Island DZ. Launch Pad: 37.0 N x 72.0 W. Launch Platform: L-1011. LV Family: Pegasus. Launch Vehicle: Pegasus XL/HAPS. LV Configuration: Pegasus XL/HAPS F22.
  • Orbcomm B5 - . Payload: Orbcomm s/n FM17. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25413 . COSPAR: 1998-046A. Apogee: 824 km (512 mi). Perigee: 813 km (505 mi). Inclination: 45.0000 deg. Period: 101.28 min. Summary: Plane B. Ascending node 61 degrees..
  • Orbcomm B6 - . Payload: Orbcomm s/n FM18. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25414 . COSPAR: 1998-046B. Apogee: 827 km (513 mi). Perigee: 810 km (500 mi). Inclination: 45.0000 deg. Period: 101.28 min. Summary: Plane B. Ascending node 59.7 degrees..
  • Orbcomm B7 - . Payload: Orbcomm s/n FM19. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25415 . COSPAR: 1998-046C. Apogee: 828 km (514 mi). Perigee: 809 km (502 mi). Inclination: 45.0000 deg. Period: 101.28 min. Summary: Plane B. Ascending node 61.1 degrees..
  • Orbcomm B8 - . Payload: Orbcomm s/n FM20. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25416 . COSPAR: 1998-046D. Apogee: 826 km (513 mi). Perigee: 811 km (503 mi). Inclination: 45.0000 deg. Period: 101.28 min. Summary: Plane B. Ascending node 61.2 degrees..
  • Orbcomm B4 - . Payload: Orbcomm s/n FM16. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25417 . COSPAR: 1998-046E. Apogee: 825 km (512 mi). Perigee: 812 km (504 mi). Inclination: 45.0000 deg. Period: 101.28 min. Summary: Plane B. Ascending node 59.9 degrees..
  • Orbcomm B1 - . Payload: Orbcomm s/n FM13. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25420 . COSPAR: 1998-046H. Apogee: 824 km (512 mi). Perigee: 813 km (505 mi). Inclination: 45.0000 deg. Period: 101.27 min. Summary: Plane B. Ascending node 60.4 degrees..
  • Orbcomm B2 - . Payload: Orbcomm s/n FM14. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25419 . COSPAR: 1998-046G. Apogee: 826 km (513 mi). Perigee: 811 km (503 mi). Inclination: 45.0000 deg. Period: 101.28 min. Summary: Plane B. Ascending node 60.4 degrees..
  • Orbcomm B3 - . Payload: Orbcomm s/n FM15. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25418 . COSPAR: 1998-046F. Apogee: 825 km (512 mi). Perigee: 812 km (504 mi). Inclination: 45.0100 deg. Period: 101.28 min. Summary: Plane B. Ascending node 60 degrees..

1998 September 23 - . 05:06 GMT - . Launch Site: Wallops Island DZ. Launch Pad: 37.0 N x 72.0 W. Launch Platform: L-1011. LV Family: Pegasus. Launch Vehicle: Pegasus XL/HAPS. LV Configuration: Pegasus XL/HAPS F23.
  • Orbcomm C1 - . Payload: Orbcomm s/n FM21. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25475 . COSPAR: 1998-053A. Apogee: 825 km (512 mi). Perigee: 811 km (503 mi). Inclination: 45.0100 deg. Period: 101.27 min. Summary: Plane C. Ascending node 181.6 degrees..
  • Orbcomm C2 - . Payload: Orbcomm s/n FM22. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25476 . COSPAR: 1998-053B. Apogee: 823 km (511 mi). Perigee: 814 km (505 mi). Inclination: 45.0200 deg. Period: 101.27 min. Summary: Plane C. Ascending node 178 degrees..
  • Orbcomm C3 - . Payload: Orbcomm s/n FM23. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25477 . COSPAR: 1998-053C. Apogee: 823 km (511 mi). Perigee: 813 km (505 mi). Inclination: 45.0200 deg. Period: 101.27 min. Summary: Plane C. Ascending node 181.8 degrees..
  • Orbcomm C5 - . Payload: Orbcomm s/n FM25. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25479 . COSPAR: 1998-053E. Apogee: 824 km (512 mi). Perigee: 813 km (505 mi). Inclination: 45.0100 deg. Period: 101.27 min. Summary: Plane C. Ascending node 181.5 degrees..
  • Orbcomm C6 - . Payload: Orbcomm s/n FM26. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25480 . COSPAR: 1998-053F. Apogee: 825 km (512 mi). Perigee: 811 km (503 mi). Inclination: 45.0100 deg. Period: 101.27 min. Summary: Plane C. Ascending node 181.5 degrees..
  • Orbcomm C7 - . Payload: Orbcomm s/n FM27. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25481 . COSPAR: 1998-053G. Apogee: 823 km (511 mi). Perigee: 813 km (505 mi). Inclination: 45.0200 deg. Period: 101.27 min. Summary: Plane C. Ascending node 181.6 degrees..
  • Orbcomm C4 - . Payload: Orbcomm s/n FM24. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25478 . COSPAR: 1998-053D. Apogee: 822 km (510 mi). Perigee: 814 km (505 mi). Inclination: 45.0100 deg. Period: 101.27 min. Summary: Plane C. Ascending node 181.7 degrees..
  • Orbcomm C8 - . Payload: Orbcomm s/n FM28. Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25482 . COSPAR: 1998-053H. Apogee: 824 km (512 mi). Perigee: 813 km (505 mi). Inclination: 45.0300 deg. Period: 101.27 min. Summary: Plane C. Ascending node 181.7 degrees..

1999 May 18 - . 05:09 GMT - . Launch Site: Point Arguello WADZ. Launch Pad: 36.0 N x 123.0 W. Launch Platform: L-1011. LV Family: Pegasus. Launch Vehicle: Pegasus XL/HAPS. LV Configuration: Pegasus XL/HAPS F27.
  • TERRIERS - . Nation: USA. Agency: NASA Greenbelt. Manufacturer: AeroAstro. Class: Technology. Type: Military technology satellite. Spacecraft: TERRIERS. USAF Sat Cat: 25735 . COSPAR: 1999-026A. Apogee: 493 km (306 mi). Perigee: 484 km (300 mi). Inclination: 97.1000 deg. Period: 94.40 min. TERRIERS was part of NASA's Student Explorer Demonstration Initiative (STEDI), which was a precursor program to the UNEX (University Explorer) series. STEDI was managed by USRA (the Universities Space Research Association) for NASA, while UNEX was to be more directly managed by NASA-GSFC. TERRIERS was to be operated by the space physics group at Boston University for ionosphere studies, and carried TESS, a set of extreme ultraviolet (EUV) spectrographs to get electron density and thermosphere emission profiles. The GISSMO instrument measured the solar EUV flux. The spacecraft was built by AeroAstro and based on HETE. TERRIERS was placed in the correct orbit, but it failed to orient its solar panel to the Sun and ran out of battery power by May 20. Controllers were optimistic that when its orbit processes to a better sun angle the satellite could be revived. Additional Details: here....
  • MUBLCOM - . Nation: USA. Agency: USA. Manufacturer: Germantown. Class: Communications. Type: Military communications satellite. Spacecraft: Microstar. USAF Sat Cat: 25736 . COSPAR: 1999-026B. Apogee: 745 km (462 mi). Perigee: 738 km (458 mi). Inclination: 97.7000 deg. Period: 99.70 min. After deploying the TERRIERS satellite, the conical Payload Adapter Fitting (1998-26E) was jettisoned at 05:21 GMT, leaving the disk-shaped MUBLCOM satellite attached to the Pegasus XL PRIMEX HAPS-Lite stage. The second HAPS burn at 05:22 GMT raised apogee to 775 km, followed by a third, apogee burn at 06:10 GMT which circularised the orbit. MUBLCOM was deployed to a 769 km x 776 km x 97.7 degree orbit. The final HAPS burn then placed the depleted HAPS stage in a lower 388 km x 722 km x 97.1 degree disposal orbit. MUBLCOM (Multiple beam Beyond Line-of-sight Communications) was an experimental satellite funded by DARPA and managed by the US Army's Communications-Electronics Command (CECOM) at Ft Monmouth, New Jersey. It was built by Orbital Sciences using the Microstar (Orbcomm type) bus and carries a payload testing hand-held radio satellite communications for the armed forces.

    Six years later MUBLCOM was the target for the DART Autonomous Rendezvous Technology mission. On April 16, 2005, DART closed within 100 m of MUBLCOM satellite, then evidently began a series of out-of-control maneuvers resulting in an in-space collission and MUBLCOM being bumped into a 3 to 5 km higher orbit. DART was deorbited while MUBLCOM, still functioned, continued on in space.


1999 December 4 - . 18:53 GMT - . Launch Site: Wallops Island DZ. Launch Pad: 37.0 N x 72.0 W. Launch Platform: L-1011. LV Family: Pegasus. Launch Vehicle: Pegasus XL/HAPS. LV Configuration: Pegasus XL/HAPS F28.
  • Orbcomm FM30 - . Mass: 45 kg (99 lb). Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25980 . COSPAR: 1999-065A. Apogee: 798 km (495 mi). Perigee: 790 km (490 mi). Inclination: 45.0000 deg. Period: 100.70 min. Summary: Seven Orbcomms launched, rather than eight as on previous flights..
  • Orbcomm FM32 - . Mass: 45 kg (99 lb). Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25982 . COSPAR: 1999-065C. Apogee: 798 km (495 mi). Perigee: 788 km (489 mi). Inclination: 45.0000 deg. Period: 100.70 min.
  • Orbcomm FM33 - . Mass: 45 kg (99 lb). Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25983 . COSPAR: 1999-065D. Apogee: 793 km (492 mi). Perigee: 780 km (480 mi). Inclination: 45.0000 deg. Period: 100.60 min.
  • Orbcomm FM34 - . Mass: 45 kg (99 lb). Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25984 . COSPAR: 1999-065E. Apogee: 795 km (493 mi). Perigee: 792 km (492 mi). Inclination: 45.0000 deg. Period: 100.70 min.
  • Orbcomm FM35 - . Mass: 45 kg (99 lb). Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25985 . COSPAR: 1999-065F. Apogee: 797 km (495 mi). Perigee: 791 km (491 mi). Inclination: 45.0000 deg. Period: 100.70 min.
  • Orbcomm FM36 - . Mass: 45 kg (99 lb). Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25986 . COSPAR: 1999-065G. Apogee: 797 km (495 mi). Perigee: 790 km (490 mi). Inclination: 45.0000 deg. Period: 100.70 min.
  • Orbcomm FM31 - . Mass: 45 kg (99 lb). Nation: USA. Agency: Orbcomm. Manufacturer: Germantown. Program: Orbcomm. Class: Communications. Type: Civilian communications satellite. Spacecraft: Orbcomm. USAF Sat Cat: 25981 . COSPAR: 1999-065B. Apogee: 798 km (495 mi). Perigee: 790 km (490 mi). Inclination: 45.0000 deg. Period: 100.70 min.

2005 April 15 - . 17:26 GMT - . Launch Site: Point Arguello WADZ. Launch Pad: 36.0 N x 123.0 W. LV Family: Pegasus. Launch Vehicle: Pegasus XL/HAPS. LV Configuration: Pegasus XL/HAPS F36.
  • DART - . Mass: 360 kg (790 lb). Nation: USA. Agency: NASA. Manufacturer: OSC. Class: Technology. Type: Rendezvous technology satellite. Spacecraft: DART. USAF Sat Cat: 28642 . COSPAR: 2005-014A. Apogee: 747 km (464 mi). Perigee: 395 km (245 mi). Inclination: 96.6000 deg. Period: 96.10 min. Delayed from April 15; October 18, 19, 26, 28; Nov. 4, 9 and 11; 2004, and March 2, 2005. Autonomous Rendezvous Technology mission, planned to guide itself to within a few metres of a US satellite. On April 16, DART closed within 100 m of the MUBLCOM satellite, then evidently began a series of out-of-control maneuvers resulting in an in-space collission and MUBLCOM being bumped into a 3 to 5 km higher orbit. Remarkably both satellites continued to function. DART then detected that it was running unexpectedly low on nitrogen cold gas used for orientation. Its autonomous software aborted further rendezvous operations and the DART was deorbited shortly thereafter.

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