STS-125

'STS-125' is a planned Space Shuttle mission to be flown by Space Shuttle ''Atlantis''. Scheduled for launch on August 7, 2008[1], the mission will serve as the fifth servicing mission for the Hubble Space Telescope, with ''Atlantis'' carrying two new instruments to the orbital observatory, alongside the replacement of a 'Fine Guidance Sensor' and the telescope's gyroscopes and batteries. The crew will also install a new thermal blanket layer to provide better insulation and a 'Soft-Capture mechanism' to aid in the safe deorbiting of the spacecraft at the end of its operational lifespan.
Otherwise known as Hubble Space Telescope Servicing Mission 4 (HST-SM4), the mission will mark the thirtieth and final flight of Space Shuttle ''Atlantis'', the last planned manned mission to the space telescope and the final 'solo' flight of a Space Shuttle Orbiter, in that all following Space Shuttle missions will involve a docking with the International Space Station. The mission's completion will seven flights remaining in the Space Shuttle program until its end in 2010, excluding two as-yet-unconfirmed Contingency Logistic Flights.
Due to the fact that ''Atlantis'' will be unable to dock with the International Space Station in the event of her heat shield becoming damaged upon launch, the mission will require ''Endeavour'' to be ready on launchpad 39B for immediate flight on the STS-400 Launch On Need (LON) rescue mission throughout ''Atlantis's mission. Indeed, due to the logistics of this mission, ''Endeavour'' will require roll out two weeks before ''Atlantis''.

Contents

Crew

Mission parameters

Mission highlights

Contingency planning

Extra-vehicular activities

STS-125 before Columbia's loss

See also

References

External links

Crew

The crew was announced on October 31, 2006. [2]
''Crewmember Name (# of Flights) - Mission Role''

★ Scott D. Altman (4) - Commander

★ Gregory C. Johnson (1) - Pilot

★ John M. Grunsfeld (5) - Mission specialist

★ Michael J. Massimino (2) - Mission specialist

★ K. Megan McArthur (1) - Mission specialist

★ Andrew J. Feustel (1) - Mission specialist

★ Michael T. Good (1) - Mission specialist

Mission parameters

★ 'Mass:' TBD

★ 'Perigee:' 486 km

★ 'Apogee:' 578 km

★ 'Inclination:' 28.5°

★ 'Period:' 95.3 min

Mission highlights

STS-125 (HST-SM04) was originally to be performed with Discovery with a new launch date not expected before May 2008. This would move the mission ahead of STS-119, ISS Assembly flight 15A. This will be the first visit to the Hubble Space Telescope for Atlantis, although it has been previously serviced twice by Discovery, and once apiece by Columbia and Endeavour.
A "Soft-Capture Mechanism" will be installed. This will enable a spacecraft to be sent to the telescope and assist in its safe de-orbit at the end of its life. It is a circular mechanism containing structures and targets to aid docking.
Two new instruments will be added:

★ The Cosmic Origins Spectrograph will be the most sensitive ultraviolet spectrograph flown on the telescope. Its far UV channel will be 30 times more sensitive than previous instruments and the near-UV twice as sensitive.

★ The Wide field camera 3, a panchromatic wide field instrument.
The infrastructure of the telescope will also be maintained and upgraded by replacing a "Fine Guidance Sensor", a set of six new gyroscopes will be installed, batteries will be replaced, and a new outer blanket layer installed to provide better insulation.

Contingency planning

To preserve NASA's post-Columbia requirement of having shuttle rescue capability, a second shuttle will be on launch pad 39-B at the time of STS-125's launch. This will constrain 39-B's deactivation and conversion for use for Ares I flight tests. This is because the orbit of the telescope rules out the 'safe haven' of the ISS (International Space Station). As a consequence, pad modifications for the Shuttle-Derived Ares I rocket, which will eventually be the launch vehicle for the ''Orion'' spacecraft, might be delayed, but according to http://nasaspaceflight.com, by only six months, as some Ares-related modifications, most notably three new lightning masts and an underground emergency bunker, will be started prior to STS-125.
However, NASA will have conducted nine flights by the time STS-125 is due to launch, with the contingency rescue missions on standby for all of these missions. The actual rescue designation for STS-125 has yet to be officially announced.^[1]
The previous Hubble Space Telescope servicing mission took place on STS-109, with one of the most spectacular launches ever witnessed at the Kennedy Space Center, as ''Columbia's dawn launch pierced through low clouds, lighting up the State of Florida in the process. Altman was also commander of STS-109, and Grunsfeld and Massimino were also on that previous flight. It would be the last time that ''Columbia'' would land safely.

Extra-vehicular activities

Five back-to-back extra-vehicular activities, also called spacewalks, are planned.

★ EVA-1: Installation of three rate sensing units (six gyros) and one battery module (three batteries)

★ EVA-2: Installation of the Cosmic Origins Spectrograph and the second battery module

★ EVA-3: Installation of the Wide field camera 3 and insulation repairs

★ EVA-4: Space Telescope Imaging Spectrograph repair and installation of a cooling system

★ EVA-5: Installation of Fine Guidance Sensor No. 3 and associated equipment.

STS-125 before Columbia's loss

STS-125 was originally planned to have flown ISS assembly mission ISS-1J. It would have delivered the Kibo Japanese Experiment Module and JEM RMS to the station. [3] Columbia was originally planned to fly the SM4 mission. Due to her weight Columbia was not the optimum orbiter for ISS assembly.

See also

★ Space Shuttle program

★ List of space shuttle missions

References

★ http://www.nasaspaceflight.com/content/?id=4489

★ http://www.nasaspaceflight.com/content/?cid=4683

★ NASA - Hubble Space Telescope Servicing Mission 4

★ Service Mission Four Factsheet

External links

★ Servicing Mission 4 at ESA/Hubble site