Date
.
Early 1968
Congress approved a follow-on Nimbus
program (Nimbus E and F).
June 1968
NASA Headquarters approved a
replacement for Nimbus B.
Nov. 1968
Congress cut $6.5 million from the
Nimbus budget, forcing the agency to modify its
plans.
Jan. 15, 1969
GSFC released an RFP for a Nimbus
spacecraft.
Jan. 17, 1969
NASA terminated Nimbus 2 operations
after it had successfully completed all its
objectives.
Jan. 22, 1969
A project approval document for
Nimbus E and F was approved at NASA Headquarters. Nimbus E
was scheduled for launch in the second quarter of 1972,
Nimbus F for the second quarter of 1973.
Mar. 12, 1969
GE submitted its proposal for Nimbus
to GSFC.
Apr. 14, 1969
Nimbus 3 was launched successfully.
Operations were ceased in March 1972.
July 1, 1969
GE's phase C contract was extended
six months; phase D was shortened from 32 to 28
months.
July 25, 1969
A Nimbus E payload was approved; six
of the originally proposed eight experiments were
retained.
July 29, 1969
Nimbus 3s IRIS failed.
Aug. 1, 1969
GSFC completed its evaluation of GE's
proposal.
Nov. 20, 1969
For Nimbus F, 12 experiments were
chosen from 33 proposals for a tentative payload; the number
was reduced to 11 in August 1970.
Nov. 26, 1969
The Nimbus program manager
recommended a Nimbus follow-on program of two flights
(Nimbus G and H).
Feb. 1970
GSFC awarded contracts for Nimbus E
experiments.
Mar. 31, 1970
GSFC awarded GE a contract for the
fabrication of the Nimbus spacecraft; the contract was
definitized in June.
Apr. 8, 1970
Nimbus 4 was launched
successfully.
Jan. 25, 1971
The number of experiments being
considered for Nimbus F was increased to 14; 12 were
approved in March.
Feb. 1972
Because of budget tightening efforts,
funds were reallocated from Nimbus to ERTS; three Nimbus
experiments under consideration were dropped. GSFC awarded
contracts for Nimbus F experiments.
July 1972
The tracking and data relay
experiment was removed from Nimbus E, but it was kept as
part of Nimbus F.
Dec. 10, 1972
Nimbus 5 was launched successfully;
operations were terminated in April 1983.
Mar. 29, 1973
NASA Headquarters sent GSFC
guidelines for the initiation of Nimbus G. Nimbus G would
provide data on pollution, oceanography, and meteorology;
launch was scheduled for early 1977.
Aug. 1, 1973
GE presented a low-cost Nimbus G
spacecraft development plan to NASA Headquarters.
Dec. 14, 1973
GE Presented a second cost proposal
to NASA for Nimbus G not to exceed $15.66 million.
Mar. 20, 1974
NASA Headquarters briefed OMB on
Nimbus G.
Apr. 1974
The launch readiness date for Nimbus
F was changed to October 1974.
Nov. 7, 1974
GSFC awarded GE a contract for Nimbus
G development.
Nov. 27, 1974
The Nimbus F launch date was changed
to May-June 1975.
Apr. 6, 1975
GSFC awarded a contract to Beckman
Instruments for a Nimbus G instrument to measure and monitor
concentrations of ozone (SBUV/TOMS).
May 1975
The launch date for Nimbus G was
estimated as late 1978.
June 12, 1975
Nimbus 6 was launched successfully;
operations ended in September 1983.
Sept. 17, 1976
NASA Headquarters reviewed the status
of Nimbus G.
Oct. 24, 1978
Nimbus 7 was launched successfully;
it was still operational in 1983.