STS-70 (70)

Discovery (21)
Pad 39-B (33)
70th Shuttle Mission
21st Flight OV-103
1st Flight Block 1 mission
24th KSC landing
9th Rollback


Terence T. Henricks (3), Commander
Kevin R. Kregel (1), Pilot
Nancy Jane Currie (2), Mission Specialist
Donald A. Thomas (2), Mission Specialist
Mary Ellen Weber (1), Mission Specialist


(Flow 1)
OPF -- 02/11/95
VAB -- 05/03/95
PAD -- 05/11/95

(Flow 2-Rollback)
VAB -- 06/08/95
PAD -- 06/15/95


TDRS-G/IUS-26, MSX-01, PARE/NIH-R-02 BDS-02, CPCG-07, STL-05(B)/NIH-C, BRIC-04, BRIC-05, SAREX-II, T-4-02, HERCULES>-03, AMOS-25, MIS-B-01, WINDEX-02, RME-III-19, MAST

Mission Objectives:

The primary mission is the launch and deployment of the 7th Tracking Data and Relay Satellite (TDRS) and will be the 6th placed in operational use. The first TDRS was launched aboard STS-6 on 4/5/83 with a scheduled lifetime of 7 years. The second TDRS (TDRS-2) was lost aboard Challenger on mission 51-L . Other TDRS satellites have flown on STS-26 (TDRS-3), STS-29 (TDRS-4), STS-43 (TDRS-5) and STS-54 (TDRS-6). The on-orbit TDRS network is currently being rearranged and will include two fully operational spacecraft occupying the TDRS East and West slots, one on-orbit fully functional spare, a nearly depleted TDRS which has exceeded its planned lifetime, and a partially operational TDRS devoted to supporting the Compton Gamma Ray Observatory GRO). It is also used to cover an area that can't be seen by the other satellites known as the Zone of Exclusion.

The TDRS system is a space-based network that provides communications, tracking, telemetry, data acquisition and command services essential to the Space Shuttle and other low-Earth orbital spacecraft such as the Hubble Space Telescope (HST), the Compton Gamma Ray Observatory (GRO), the Upper Atmosphere Research Satellite (Mission Control Center (MCC) will control the shuttle, and the Inertial Upper Stage (IUS) control center at Onizuka Air Force Base in Sunnyvale California will control the boster stage. Deploy operations will begin six hours into the mission. Once deployed, the TDRS satellite has a wingspan of 57 ft. TDRSS-G will add to the complement of satellites already in orbit.

Secondary objectives of the mission are to fulfill the requirements of the Physiological and Anatomical Rodent Experiment / National Institutes of Health-Rodents (PARE/NIH-R); Bioreactor Demonstration System (BDS), Commercial Protein Crystal Growth (CPCG); Space Tissue Loss/National Institutes of Health-Cells (STL/NIH-C); Biological Research in Canisters (BRIC); Shuttle Amateur Radio Experiment-II (SAREX-II), Visual Function Tester-4 (VFT-4); Hand-Held, Earth Oriented, Real-Time, Cooperative, User-Friendly, Location-Targeting and Environmental System HERCULES); Microcapsules in Space-B (MIS-B); Windows Experiment (WINDEX); Radiation Monitoring Equipment-III (RME-III); and the Military Applications of Ship Tracks (MAST).

STS-70 will mark the maiden flight of the new Block 1 orbiter main engine. Engine number 2036 features the new high-pressure liquid oxygen turbopump, a two-duct powerhead, baffleless main injector, single-coil heat exchanger and start sequence modifications. The modifications are designed to improve both engine performance and safety. The Block I engine will fly in the number one position on Discovery. The other two engines are of the existing Phase II design.


Launch July 13, 1995 at 9:41:55.078 a.m. EDT. The launch window was 2 hours 30 min. The hatch was closed at 8:13am EDT and the count proceeded smoothly until T-31 sec. The count was held for 55 seconds at T-31 sec by the Booster Range Safety Engineer (CBRS) Tod Gracom at the LCC C-5 Console due to fluxuations seen on the external tank automatic gain control (AGC) ET range safety system receiver . Launch Commit Criteria contigency procedures were worked and the count then proceeded on schedule.

STS-70 had originally moved ahead of the launch of STS-71 because of a delay in the launch of the Russian Spektr laboratory module to the Russian space station Mir. However, on 5/31/95 NASA shuttle managers assessed damage to the external tank of STS-70 caused by nesting Flicker Woodpeckers. The damage consisted of about 71 holes (ranging in size from 4 inches in diameter to 1/2 inch in diameter) in the ETs thermal protection foam insulation. Technicians installed safeguards against additional damage. On 6/2/95, NASA managers decided to delay the launch of Discovery on Mission STS-70 in order to make repairs to foam insulation on the vehicle's external fuel tank. STS-71 was moved ahead of STS-70 and Discovery was rolled back to the VAB.


Altitude: 160 nm (184 statute miles)
Inclination: 28.45 degrees
Orbits: 143
Duration: 8 days, 22 hours, 20 minutes, 5 seconds.
Distance: 3.7 million miles


ET : SN-71
SSME-1: SN-2036
SSME-2: SN-2019
SSME-3: SN-2017


KSC July 22,1995 at 8:02 a.m. EDT on Runway 33. Nose gear touchdown at 8:02:11am EDT (Mission Elapsed Time of 8days 22hr 20min and 16sec) with wheels stop at 8:02:57am (MET of 8 days 22hr 21min and 2 sec.)

The KSC landing opportunity on 7/22/95 at 6:26 a.m. EDT was waived off due to marginable yet improving weather conditions at KSC. The KSC landing opportunities at 7:54am EDT and 9:31 a.m on 7/21/95 were waived off due to a buildup of ground fog over the Shuttle Landing Facility.

Two landing opportunities were available at the Kennedy Space Center Saturday. The first called for a deorbit burn at 4:26 a.m. CDT with a landing at 5:26 a.m. CDT. the second opportunity calls for a deorbit burn at 6 a.m. CDT with a landing at 7:02 a.m. If the weather didn't cooperate at KSC, Discovery would have been directed to land at California's Edwards Air Force Base. The one Edwards opportunity would have started with a deorbit burn at 7:28 a.m. CDT with a landing at 8:29 a.m. CDT.

Flight Director Rich Jackson directed the five STS-70 astronauts to remain aloft for another day after poor visibility prevented Discovery's homecoming on two consecutive landing opportunities. Landing support was not called up at the backup landing site at California's Edwards Air Force Base for today.

Discovery's astronauts were informed that their landing had been waved off for the day at 7:10 AM CDT after astronaut Steve Oswald, flying weather reconnaissance in a Shuttle Training Aircraft over the landing strip, reported that he could not see the 3- mile long runway from his vantage point.

The STS-70 crew had two opportunities to land at the Kennedy Space Center on Friday 7/21/95. For the first opportunity, Discovery's orbital maneuvering system engines would have fired for the deorbit burn at 6:53 a.m. EDT, resulting in a touchdown in Florida at 7:54 a.m. EDT. The deorbit burn for the second opportunity would have occured at 8:28 a.m. EDT, with landing at 9:31 a.m. EDT. Weather forecasters watched the formation of scattered cloud layers and ground fog that prohibited a KSC landing There are two KSC landing opportunities on Saturday (6:26 am and 8:01 am EDT) and one Edwards Air Force Base opportunity (9:28am EDT).

Mission Highlights:

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