STS-125: Mission to Hubble
Hubble above Earth

The STS-109 crew took this picture of the Hubble Space Telescope after completing the last servicing mission in 2002. Image Credit: NASA

For the Hubble Space Telescope, the STS-125 space shuttle mission will be both an ending and a new beginning.

On the one hand, the spring 2009 flight will be the last time the space shuttle visits Hubble. The mission marks an end to a long relationship between the two spacecraft.

On the other hand, that visit will provide Hubble with a new beginning. Astronauts will work to make the telescope more powerful than ever. They will prepare it for several more years of astronomical observations.

The Hubble Space Telescope was launched aboard space shuttle Discovery in April 1990. Since that time, the space shuttle has visited Hubble four more times. Astronauts have made repairs and upgraded equipment on Hubble. They have done this by performing spacewalks outside the telescope, which is the size of a large school bus and would weigh as much as two adult elephants.

STS-125 will be the shuttle's fifth and final rendezvous with Hubble. The crew of the space shuttle Atlantis will conduct five spacewalks. Astronauts will install two new instruments and repair two others. They also will make other equipment repairs and upgrades to lengthen the life of the telescope.

Astronaut Scott Altman is the commander of STS-125. This will be his fourth spaceflight. It will be his second time to command a mission to Hubble. The mission’s pilot will be Gregory C. Johnson. He will be making his first spaceflight.

Like Altman, two of the STS-125 mission specialists have visited Hubble before. John Grunsfeld made five spacewalks to repair Hubble on two previous visits. He will make three more spacewalks on STS-125. Astronaut Mike Massimino made two spacewalks on his previous trip to Hubble. He will make two more on this flight.

Atlantis' other three mission specialists will be making their first spaceflights. They are Michael Good, Megan McArthur and Andrew Feustel. Feustel will work with Grunsfeld on spacewalks. Good will partner with Massimino. McArthur will operate the shuttle's robotic arm.

Two new instruments will be installed on the mission. The Wide Field Camera 3 will provide high-resolution images in a range of wavelengths. The Cosmic Origins Spectrograph will break down light to study the formation of stars, galaxies and the universe.

The STS-125 crew in orange launch and entry suits

The seven members of the STS-125 crew are (from left) astronauts Mike Massimino, Michael Good, both mission specialists; Gregory C. Johnson, pilot; Scott Altman, commander; Megan McArthur, John Grunsfeld and Andrew Feustel, all mission specialists. Image Credit: NASA

In its 19 years, Hubble has helped scientists learn about the universe. Using Hubble, scientists determined the universe is 13.7 billion years old. They learned more about how planets and galaxies form. They learned that the rate at which the universe is expanding is getting faster because of something called "dark energy." Scientists know very little about dark energy today. They hope the improvements to Hubble will help them learn more.

STS-125 will be unusual in another way. NASA has two launch pads for space shuttles. When Atlantis launches, Endeavour will be on the other pad. Unlike the other remaining shuttle flights, STS-125 will not visit the International Space Station. Because Hubble is in a different orbit, Atlantis would not be able to travel to the space station if something went wrong. Endeavour will launch in the unlikely event that Atlantis has problems requiring a rescue flight. NASA does not expect any problems. Improvements on recent flights have made the shuttle safer than ever. But if there is a severe issue that can't be repaired in orbit, NASA will be ready.

With its ability to study distant worlds, the Hubble Space Telescope is important to NASA's mission of exploration. In repairing and improving Hubble, the STS-125 shuttle mission is a step toward the future of spaceflight. NASA currently is working to carry out a long-term plan that will lead to humans' returning to the moon and beyond.

NASA is committed to working with formal and informal educators of science, technology, engineering and mathematics. Through hands-on, interactive educational activities, NASA is engaging students, educators, families, the public and all agency stakeholders to increase scientific and technological literacy in the United States.

Related Resources
Hubble Inspires Wonder Educator Resource Page
Mission to Hubble
Hubble Space Telescope
Visiting an Old Friend
HubbleSite   →
The Hubble Space Telescope   →
NASA Education Web site

David Hitt/NASA Educational Technology Services