Engineering topics

Ross, D. J.

Publications and source records attributed to Ross, D. J..

4 records

NASA NTRS1983

Missions to the asteroid Anteros and the space of true anomalies

Three opportunities for missions to rendezvous ballistically with the earth-crossing asteroid Anteros are studied to illustrate the requirements for a trip to a near-earth minor planet. The rationale, sample payload, spacecraft requirements and trajectory characteristics of these opportunities are typical of a rendezvous mission to an accessible near-earth object. Round trip ballistic trajectories to return small samples of the asteroid with launch dates between 1985 and 2000 are also presented. Contours of minimum total delta drawn in the space of launch and arrival true anomalies, given the designation Prime Rib curves, are introduced as a useful tool for mission design.

Hulkower, N. D.↗

NASA NTRS1981

Optimal orbital transfers and prime rib curves for mission design

Battin's work on optimal one impulse transfers from circular orbits is extended. Optimal one impulse trajectories from orbits of arbitrary eccentricity through a specified point are determined. This work is then further extended to optimal two impulse transfers between massive planets. Curves derived using this technique are presented showing flyby and rendezvous Delta V requirements for all combinations of launch and arrival true anomalies. Similar curves for times of flight corresponding to the trajectories with minimum total Delta V are derived using Lambert's methods. Possible further extension of these techniques are outlined. The use of these curves for mission design is presented in a companion paper by Hulkower and Ross (1971).

Ross, D. J.↗

NASA NTRS1981

A mission to rendezvous with Anteros

A modest mission to rendezvous with the earth-approaching asteroid, Anteros, is studied. A 10-day launch window of May 16 to 25, 1985 is suggested. The times of flight range from 402 to 455 days and the launch energies per unit mass range from 32.9 to 37.3 km/sq sec. Rendezvous can be achieved with a postlaunch change in velocity of from 562 to 1001 m/sec. A mass of at least 615 kg can be delivered into orbit about the asteroid by the Titan 34D/IUS Two-Stage with 50 to 100 kg available for scientific instrumentation. The 1985 opportunity is compared to the 1987 trajectory identified by Niehoff (1977). Rendezvous opportunities are examined in the space of launch and arrival true anomalies.

Hulkower, N. D.↗

NASA NTRS1980

Material capture by double lunar gravity assist

The equations yielding the performance of a single lunar flyby in removing incoming hyperbolic excess velocity to capture payloads on interplanetary trajectories are briefly derived. The impossibility of using a single lunar flyby to capture a body entering the earth-moon system with a hyperbolic velocity in excess of about 1.9 km/s is discussed, and a method of using a double flyby of the moon to significantly improve this performance is developed. The equations for achieving a double lunar flyby are derived by solving the orbital equations and Lambert's problem both for the incoming trajectory in the plane of the moon's orbit and for arbitrary declination. For the in-plane case it is shown that the maximum removable hyperbolic excess velocity is 2.2687 km/s. For the inclined case, it is shown that the use of a double lunar flyby allows capture for declinations in excess of 54 degrees, and that for declinations less than 38 degrees the double lunar flyby offers better performance than the single lunar flyby.

Ross, D. J.↗