美國宇航局準備實施小行星捕捉和登陸計劃

美國總統(tǒng)奧巴馬政府一位高級官員4月6日向媒體證實，美國宇航局(NASA)將加速對接近地球的小行星的勘測，在十年之內派遣宇航員登上小行星帶回樣品，最終目標是火星登陸計劃。這一表態(tài)或標志著“捕捉”小行星計劃即將開始進入實際操作階段。

據美國全國廣播公司6日報道，這位不愿透露姓名的負責人表示，該任務是為了加快“完成總統(tǒng)交辦的任務”，奧巴馬總統(tǒng)曾下達目標，在2025年之前，將宇航員送到一顆小行星上。

其表態(tài)證實了美國參議院科學和太空委員會主席比爾·尼爾森(Bill Nelson)5日的公開發(fā)言，后者表示，美國宇航局準備實施小行星捕捉和登陸計劃，有可能提前4年實現(xiàn)宇航員登上小行星的目標。

科學家們認為，與其讓宇航員到遙遠的地方冒險，還不如把小行星捕捉回來再登陸，既安全又能完成任務，帶入近月軌道后的小行星還可作為繞月空間站或太空基地，未來登陸火星時還可作為一個空間中轉站。

今年年初，美國宇航局向白宮提交了一份“捕捉小行星方案”，總投資超過26.5億美元，本月3日已就這一計劃向國會提出了1億美元的啟動資金申請，標志著這項史無前例的方案或即將進入實操階段?！斑@真是一個聰明的概念，”尼爾森在新聞發(fā)布會上說，“找到一個理想的候選小行星，用機器捕獲并把它帶回來?！?/p>

根據“捕捉小行星”計劃，NASA將發(fā)射一艘特制捕捉艙，其在接近直徑約25英尺、重約500噸的目標時會釋放出一個大袋子，利用束帶包裹小行星，最終在太陽能的推進下，將小行星拖至近月軌道。

顯然這趟使命是一個空間技術的試驗場，NASA的未來火箭系統(tǒng)將派上用場。此外，多家私人航天機構也表示要執(zhí)行類似計劃。俄羅斯遭受突如其來的流星雨襲擊事件，使得科學家將目光更多地轉移到危險級近地小行星上來。

尼爾森表示，小行星捕捉計劃能幫助美國開發(fā)出“扭轉”危險小行星軌道的技術，也為2030年左右將宇航員送往火星做準備。美國宇航局近地天體項目主管約曼斯(Donald Yeomans)認為，這項計劃不會威脅地球安全，因為如果這種大小的小行星進入地球大氣層會被燒毀。

美國媒體評論，如果這一計劃得以實施，將是人類首次“操控”天體，是人類第一次為了生存而修改太空。政府文件描述這是一項鼓舞人心的任務，因為它“將人類送到比以往更遠的地方”。

Of fi cial Con fi rms NASA Plan to Capture an Asteroid

Rumors have been leaking out for over a week, but now according to Alan Boyle at NBC News’ Cosmic Log, a senior Obama administration official has con fi rmed that $100 million is being sought for NASA’s budget request for the coming fi scal year for work to allow a robotic spaceship to capture a small asteroid and park it near the Moon for astronauts to explore. The spacecraft would capture a 500-ton, 7- meter (25-foot) asteroid in 2019.

Then using an Orion space capsule, a crew of about four astronauts would stat on-keep with the space rock in 2021 to allow for EVAs for explorat on. This plan would accelerate NASA’s deep space missions with Orion and prepare crews for going to Mars.

NBC news quoted the oき cial— who spoke on condition of anonymity because there was no authorization to discuss the plan publicly — as saying the mission would “accomplish the president’s challenge of sending humans to visit an asteroid by 2025 in a more cost-effective and potentially quicker time frame than under other scenarios.”

A week ago, Aviation Week reported that NASA was considering this asteroid mission,which was proposed by the Keck Inst tute for Space Studies last year.Keck’s proposal had a price tag of$2.6 billion, but no cost estimate for the space agency’s version has yet been released.

Then on April 5, the Associated Press quoted U.S. Sen.Bill Nelson, D-Florida, Nelson,chairman of the Senate science and space subcommittee, that President Obama is putting $100 million in planning money for the accelerated asteroid mission in the 2014 budget that comes out next week. The money would be used to fi nd the right small asteroid.

“It really is a clever concept,”AP quoted Nelson said in a press conference in Orlando. “Go find your ideal candidate for an asteroid.Go get it robotically and bring it back.”

This would be the first time ever an object in space of this size would be manipulated in such a manner.

Donald Yeomans, who heads NASA’s Near Earth Object program,was quoted that while there are thousands of asteroids around 25-feet, finding the right one that comes by Earth at just the right time to be captured will not be easy. And once a suitable rock is found it would be captured with the space equivalent of “a baggie with a drawstring. You bag it. You at ach the solar propulsion module to de-spin it and bring it back to where you want it.”

A 7- meter (25-foot) asteroid is not a threat to Earth because asteroids of that size would burn up in Earth’s atmosphere.

The official quoted by NBC said the plan has been under discussion for months, but after February’s meteor blast over Russia, the plan gained tract on.