Jonathan’s Space Report No. 472 -16 Feb 2002
Shuttle and Station
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The next Shuttle launch is STS-109, the Hubble Servicing Mission 3B.
Orbiter OV-102 Columbia will fly to rendezvous with HST, grapple it with
the RMS and berth it on the FSS pallet in Columbia’s payload bay. In the
course of five spacewalks, the crew will install new equipment on HST.
This is the first flight of Columbia since the launch of Chandra in
1999; it’s been in the garage undergoing refurbishment.
In the first two spacewalks, two new solar arrays will be installed, and
the two old arrays will be stowed on the RAC carrier. The RWA-1R
reaction wheel assembly on the MULE carrier will replace the faltering
RWA-1 in the telescope. The third spacewalk is the most difficult, as
HST will be entirely powered down while astronauts replace its power
controller unit, not designed for on-orbit replacement. They’ll have to
cover some key equipment with thermal blankets before the shutdown. The
fourth spacewalk will see the astronauts remove the European FOC camera,
aboard HST since launch in 1990, and replace it with the new ACS
(Advanced Camera for Surveys). They will also install the CASH wire
harness, part of the aft shroud cooling system. On the final spacewalk,
the astronauts will install the NCS (NICMOS cooling system) cryocooler
in the aft shround and the associated NCS radiator on the telescope’s
exterior. The NICMOS infrared camera has been idle since its original
thermal control system failed, and it’s hoped that NCS will allow it to
resume science. On the next servicing mission, an extra cooling system,
the ASCS, will be connected to ACS and STIS.
Jonathan’s cargo manifest estimate:
Mass/kg(middeck) 4 EMU spacesuits 480?
Bay 4 RAC (Rigid Array Carrier) 2393
Bay 7-8 SAC (Second Axial Carrier) 2517
Bay 11 FSS (Fixed Servicing Structure) 2111
Bay 12 MULE (Multi Use Light Eqpt Carrier) 1409
Sill RMS arm No 201 410
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Total 9320?
The RAC carries the two folded SA-III rigid solar arrays
which will replace the SA-II roll-up arrays. It calso carries
the DBA2 diode box assembly which controls the arrays, and
a wire harness and containers associated with the NICMOS
cooling system. The RAC is a Spacelab pallet, and it’s possible
that it is the same pallet that flew as ORUC on the three
earlier servicing missions (and probably on earlier flights,
but I don’t know the pallet’s serial).
The SAC is a specially designed pallet that flew on the first two Hubble
SM flights, STS-61 and STS-82. On this flight it carries the ACS camera
up (and the FOS camera down) as well as the NCS cryocooler, the PCU-R
power controller, the CASH wire harness, and the thermal covers used in
the PCU replacement.
The FSS first flew on STS 41-C (the Solar Max Repair) and was reused for
each of the HST SM flights. It carries the BAPS Berthing and Positioning
System, which is the docking ring for HST. Stowed on the FSS are a
support post for BAPS and a cover for the HST low gain antenna.
The MULE carries the NCS radiator, the NCS electronics support module,
and the RWA-1R reaction wheel unit. MULE first flew on STS-48 carrying
the UARS satellite, and then on STS-95 carrying the HOST payload which
tested out the NCS.
With the removal of FOC, the COSTAR device (which deployed contact
lenses for the original instruments) is obsolete, since the newer
instruments make the corrections to the incorrect HST mirror internally.
A final servicing mission will replace WFPC-2 and COSTAR with the WFC-3
and COS instruments.
Let’s review the list of HST instruments in each of the five
instrument bays:
Radial instrument: WFPC (1990-1993) Optical imaging
WFPC-2 (1993-2004?) Optical imaging
WFC-3 (2004?) Optical imaging (planned)
Axial +V3/+V2: FOC (1990-2002) UV imaging
ACS (2002?-) Optical/UV imaging
Axial +V2/-V3 HSP (1990-1993) Photometer
COSTAR (1993-2004?) Corrective optics for
FOC, GHRS, FOS
COS (2004?) Spectrograph (planned)
Axial -V3/-V2 GHRS (1990-1997) High res spectrograph
STIS (1997-) Spectrograph
Axial -V2/+V3 FOS (1990-1997) Low res spectrograph
NICMOS (1997-) IR imaging
Launch of STS-109/HST SM-3B is scheduled for Feb 28. Crew are Scott
Altman (commander), Duane Carey (pilot), Nancy Currie (flight engineer),
John Grunsfeld (payload commander and spacewalker), Rick Linnehan, James
Newman, and Michael Massimino (mission specialists and spacewalkers).
Grunsfeld, on his fourth flight, is the Ph.D. astronomer on the crew,
and we his earthbound colleagues will be eagerly looking over his
shoulder and wishing him well.
The International Space Station lost attitude control on Feb 4 for
several hours. After Zvezda computers developed communications problems
and failed to transfer data to the US gyros on the Z1 module, the GNC
MDM computer on the US side stopped stabilizing the station. The
computer problems also prevented Z1 from handing over control to the
backup thruster system on Zvezda.. At 1318 UTC the Station tumbled, in
danger of losing electrical power, and experiments were shut down as
systems were put in emergency mode. In fact, the crew were able to
manually point the US solar arrays, preventing any loss of power. The
station was restored to operation later in the day, with attitude
control resuming at 1843 UTC on thrusters and 1920 UTC on gyros.
Although I don’t think this situation endangered the crew, it was still
potentially quite serious – more so perhaps than the tone of NASA’s
press release would lead one to believe, and indeed an internal status
report admitted `free drift with GNC MDM nonfunctional can become quite
problematic’.
The rapid response of ground controllers and crew in fixing things is
good news and shows that even when the station’s systems are massively
degraded, it can be recovered (albeit one would rather not reach that
point in the first place). Losing attitude control can be really bad
news – Japan’s Yohkoh observatory is still cold and almost dead two
months after a comparable problem, and is unlikely to be revived. Of
course, spacecraft with human crews are built with more redundancy
anyway, and as in this case the astronauts contribute to keeping the
systems going, so such vehicles are less likely to be lost, but some
observers of the Station program had expressed concern that its
fault-tolerance margins were too slim.
Recent Launches
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Japan’s second H-2A rocket was launched on Feb 4. The MDS-1 was deployed
successfully but no contact has been made with DASH.
The H-2A rocket is developed by Japan’s applications space agency NASDA.
The first launch used the basic H-2A 202 variant with the 4S fairing.
The 202 consists of two SRB-A large solid boosters, the cryogenic H-2A
main stage with the LE-7A engine, and the H-2A second stage with a
cryogenic LE-5B engine. This second H-2A was the 2024 variant, which
features an extra set of four smaller Thiokol Castor IVXL solid boosters
in addition to the two SRB-As. It used the 4/4D-LC fairing which has an
extra cylindrical adapter containing a second payload. On this test
flight, the upper satellite position was basically empty, but attached
to the adapter was the VEP-3 monitoring payload and the DASH reentry
test satellite. The main payload, MDS-1, was carried in the lower
position.
Launch was at 0245 UTC from Tanegashima Space Center’s Yoshinubu
complex. The second stage began its first burn at 0251 UTC and at 0257
UTC entered a 500 km circular parking orbit. After a 12 minute coast the
second burn put stage 2 in geostationary transfer orbit. At 0315 UTC the
small DASH vehicle was meant to separate from the upper adapter, but
this apparently did not occur. At 0325 UTC VEP-3/upper adapter/DASH
combination separated from the second stage, followed by
two semi-cylindrical side panels, revealing the previously
enclosed MDS-1 satellite which was ejected at 0331 UTC. At 0425 UTC the
second stage was scheduled to make a third burn to test engine restart,
completing the H-2A-2F mission.
MDS-1 is NASDA’s Mission Demonstration Satellite, built by NEC with a
mass of 449 kg. The satellite is a technology demonstrator to
flight-qualify commercial subsystems, including a parallel computer, a
solid state recorder, a nickel-hydrogen battery, and solar cells. It
carries a space environment experiment to monitor heavy ions and
magnetic fields. MDS-1 is 3.3m by 1.6m in size after deployment
of its two solar panels.
The upper adapter is a 1.0m long 4.0m diameter cone, with a mass of
perhaps 100 kg or so. The VEP-3 launch instrumentation package mounted
on top has a mass of 33 kg. The side adapter panels are halves of a
4.1m long 4.0m diameter cylinder.
DASH (Demonstrator of Atmospheric Reentry System and Hypervelocity) is a
small secondary payload built by ISAS, the scientific space agency whose
operations are to be merged with NASDA over the next few years. DASH’s
mission was to test the reentry system for the MUSES-C asteroid probe.
The main spacecraft is 0.7 x 0.5m in size with a mass of 70 kg including
the solid deorbit motor and two small orbit adjust thrusters. Attached
to this is a reentry capsule which is 0.4m in diameter and 0.2m high,
with a mass of only 16 kg. The plan was to fire the deorbit motor three
days after launch, then separate the reentry capsule which would enter
the Earth’s atmosphere at 10 km/s and land in the Hodh el Gharbi region
of Mauritania at about 8.5W 17.2N. Typical satellite reentries are at
only 7.5 km/s, while hyperbolic (escape) velocity at the top of the
atmosphere is over 11 km/s, so DASH would have been travelling much
faster than typical reentry vehicles, but not quite at escape velocity.¥R-°3E
Space Command has cataloged three objects in a 480 x 35740 km x 28.5 deg
orbit. These three objects are presumably MDS-1, the DASH/VEP-3/adapter
combination, and the H-2A second stage, but it is not yet clear
which is which or where the side adapter panels are.
Orbital Sciences successfully launched a Pegasus XL rocket on Feb 5,
carrying NASA’s HESSI solar telescope into orbit. The L-1011 Stargazer
aircraft took off at 1929 UTC from the Cape Canaveral Skid Strip
RW30/12, and headed out to the drop area at 28.0N 78.5W over the
Atlantic. Drop was at 2058 UTC, with ignition 5 seconds later. The three
stage Pegasus reached orbit at 2107 UTC and separated from HESSI a
minute later in a 588 x 609 km x 38 deg orbit. On the first pass it was
confirmed that the solar panels had opened.
HESSI, the sixth Small Explorer, is a Spectrum Astro satellite derived
from the SA-200S design, with a mass of 304 kg carrying a rotating
modulation collimator transform telescope. The satellite rotates at 15
rpm, imaging hard X-ray flares from the Sun by reconstructing the
Fourier components from the time modulation of the flux through a set of
9 grids each 9 cm in diameter. It is expected to make images with a
resolution of 2 arcseconds at 40 keV energies and 36 arcseconds at 1 MeV
energies. Launch delays mean HESSI has missed some of the best flares at
solar max, but it should still see quite a few reasonably big ones.
Five Motorola Iridium satellites were launched from Vandenberg on Feb 11
by a Boeing Delta 7920-10C rocket. The satellites are owned by Iridium
Satellite LLC, the new company that bought out the bankrupt Iridium LLC,
and this is the first system replenishment launch since the bankruptcy.
If anyone knows the individual designations or serial numbers of
the five new satellites, please let me know and I’ll update everyone
in the next report.
Table of Recent Launches
———————–
Date UT Name Launch Vehicle Site Mission INTL.
DES.
Jan 16 0030 Milstar FLT-5 Titan Centaur Canaveral SLC40 Comms 01A
Jan 23 2347 Insat 3C Ariane 42L Kourou ELA2 Comms 02A
Feb 4 0245 MDS-1 ) H-2A Tanegashima Tech 03A
DASH ) Tech 03
VEP-3 ) Tech 03
Feb 5 2058 HESSI Pegasus XL Canaveral Astronomy 04A
Feb 11 1743 Iridium ) Delta 7920 Vandenberg SLC2W Comms 05A
Iridium ) 05B
Iridium ) 05C
Iridium ) 05D
Iridium ) 05E
Current Shuttle Processing Status
_________________________________
Orbiters Location Mission Launch DueOV-102 Columbia LC39A STS-109 2002 Feb 28 HST SM-3B
OV-103 Discovery VAB Maintenance
OV-104 Atlantis OPF Bay 2? STS-110 2002 Apr 4 ISS 8A
OV-105 Endeavour OPF Bay 1? STS-111 2002 May 2 ISS UF-2
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| Jonathan McDowell | phone : (617) 495-7176 |
| Harvard-Smithsonian Center for | |
| Astrophysics | |
| 60 Garden St, MS6 | |
| Cambridge MA 02138 | inter : jcm@cfa.harvard.edu |
| USA | jmcdowell@cfa.harvard.edu |
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