IBEX

Launch data: Designation  33401 / 08051A Launch date  19 Oct 2008 - 17:47 UT Launch site  Kwajalein Island, RW06/24 Launch vehicle  Pegasus-XL (Star-27) Mission  Government: Space Physics (Astronomy) Deep Highly Eccentric Earth orbit: Perigee / Apogee  7000 x 320000 km Eccentricity  9,21E-01 Inclination  11 deg Period  8 days

Spacecraft data: Prime contractor  Orbital Sciences Corp. Operator  NASA/Goddard Space Flight Center Platform  Orbital Microstar bus Mass at launch  107 (462?) kg Dry Mass  80 kg Basic shape  octagonal cyl. Dimension (m)  0.6m high, 1.0m dia Solar array   Stabilization   DC power   Design lifetime  still active

Workers at Vandenberg Air Force Base, Calif., make adjustments before installing the fairing around NASA's Interstellar Boundary Explorer, or IBEX, spacecraft. Credit: NASA

Mission details:

• NASA's Interstellar Boundary Explorer, IBEX, was launched on Oct 19 by an Orbital Sciences Pegasus XL.
• IBEX carries two ENA (Energetic Neutral Atom) cameras, to map out the boundary of the heliosphere (the edge of the solar system where the solar wind meets the interstellar medium). Shocks at the heliospheric boundary accelerate neutral atoms to high speeds; those atoms travel in straight lines, so the IBEX detectors in high Earth orbit can tell which direction they came from, and make an all-sky map of the less and more energetic parts of the heliosphere.
• The L-1011 aircraft took off from RW06/24 at Kwajalein, 1651 UTC Oct 19, 2008. The mission events were as follows:
  • Pegasus Drop at 1747:22.64 UTC over 167.6E 10.5N, azimuth 81.5 deg
  • Stage 1 ignition 1747:28
  • Stage 1 burnout Drop + 1:21
  • Stage 1 sep Drop + 1:30
  • Stage 2 burn Drop + 1:33
  • Fairing sep Drop + 2:18
  • Stage 2 burnout Drop + 2:47
  • Stage 2 sep Drop + 4:57 ?
  • Stage 3 burn Drop + 5:05
  • Stage 3 burnout Drop + 6:22
    Orbit insertion at 200 x 200 km x 11 deg
  • Stage 3 spinup Drop + 7:47
  • Stage 3 sep Drop + 8:22
  • Adapter cone sep - Unknown, guessing Drop + 8:25?
  • Star 27H motor burn - Unknown, guessing Drop + 8:30?
  • Star 27H motor burnout - Unknown, guessing Drop + 9:16?
  • Star 27H sep from IBEX - Unknown, guessing Drop + 12:38?
• This leaves four objects in orbit:
  • Stage 3 Orion 38 motor, in 210 x 413 km x 11 deg orbit Mass probably 202 kg, cylinder + nozzle size 1.4m long 1.0m dia
  • Adapter cone, in 210 x 413 km x 11 deg orbit Mass unknown, may be around 10 kg, cone frustrum size 0.6m long 0.7 to 1.0m dia
  • Star 27H (TE-M-1157) motor, in 219 x 250281 km x 11.0 deg orbit. Mass 27 kg size 1.2m long 0.7m dia. Initial mass was 368 kg prior to ignition of solid propellant The motor may reenter around Oct 25 after its first orbit.
  • IBEX spacecraft, in 219 x 250281 km x 11.0 deg orbit Mass 107 kg full 80 kg dry, octagonal cyl. size 0.6m high 1.0m dia based on Orbital Microstar bus. Reached first apogee around 0100 UTC on Oct 22. Will use hydrazine thruster to raise perigee to 7000 km.
• Mass estimates total 485 kg for items 2,3,4 prior to SRM ignition, which is a little larger than the 462 kg reported by NASA.
• On Jan 1, 2010 the IBEX spacecraft is in a 8038 x 307710 km x 30.3 deg orbit almost at lunar distance.
• Jan. 2012: NASA's Interstellar Boundary Explorer, has detected atoms from interstellar space streaming by Earth, finding the material is different from the chemical make-up of the solar system.
  The IBEX satellite observed hydrogen, oxygen, neon and helium atoms that originated in interstellar space, the vacuous medium between stars in the Milky Way galaxy.

External links:

• EOportal.org Satellite description