"One Small Spin", a short story by John G. Hemry a.k.a. Jack Campbell, first published in Analog Science Fiction and Fact, September 1997, reprinted in the 2013 collection Ad Astra.
NASA is having problems with its robotic Mars explorers:
"There must be some way to free Rover I from that patch of dust."
"I'm afraid not, Doctor Singleton. We've tried everything, even using the sampling probes to dig in for leverage, but Rover I just got too deep into the fine sand to pull itself out unaided."
"Unaided? what sort of aid does it need?"
"Actually, a small push would do the job, or a tug on an extended sampling arm."
"That doesn't do us any good."
"No, sir, but at least Rover I can examine the portion of the Martian surface within the radius of its sampling probes."
"How large an area is that?"
"About four square meters."
Rovers II, III, and IV meet with similar problems. Fivally, Rover V is a success:
Commander Halstead shifted uncomfortably, trying for the millionth time to fully stretch in the small compartment that had been home for months. His head jerked as the communications panel buzzed to warm of an incoming message.
"FODMAC, this is Houston. Rover V has encountered difficulty deploying from the pad of the landing vehicle. Conduct an egress and carry out necessary maintenance."
Halstead's heart leaped. "Roger, Houston. I understand you desire I conduct a landing on Mars near the Rover."
Long minutes passed as light waves crawled back and forth through the emptiness, before Houston's reply finally roared forth. "Negative, FODMAC! Negative! Your reply used improper and unauthorized terminology and has been purged from system records. We repeat, you are to conduct an egress using the IEM and achieve necessary proximity to Rover V to conduct any required maintenance, then return to the FODMAC ASAP. Do you understand?
"Yeah, Houston, I understand."
A trail of footprints marked the Martian soil from the still-smoking site of the IEM touchdown to the pad where Rover V sat like a huge, ugly stamen in the middle of a petal formed by access panels that had dropped open on every side. Halstead glared sourly down at the machine, noting that the retaining clip on the left rear quarter of the Rover had failed to release and was holding it captive. Pulling out a long screwdriver, he bent awkwardly, inserting the tool inside the latch and tugging. The latch popped open and retracted, freeing the Rover, which immediately surged into motion, seeming to bustle merrily away across the red landscape.
Question at NASA press conference:
"Excuse me, Doctor Singleton, but rumors persist that a manned expedition was somehow integrated with the Rover program and played a role in this latest success. Can you comment on those rumors?"
"I do not know why this kind of irresponsible rumor-mongering continues to be given credence. This sort of innuendo has surfaced before and our comments are on record."
"Nevertheless, Doctor, can you categorically deny any manned involvement in the Rover program?"
"Sir, every line of the Rover mission plan, funding, authorization, and mission objectives is available on-line for your review. Use any keywords you want to search through them. I can categorically state you will find no reference to a manned mission to Mars therein. Does anyone else have questions?"