Robert Mueller's jam-packed fall schedule

WASHINGTON, DC - JUNE 21:  Special counsel Robert Mueller (2nd L) leaves after a closed meeting with members of the Senate Judiciary Committee June 21, 2017 at the Capitol in Washington, DC. The committee meets with Mueller to discuss the firing of former FBI Director James Comey.  (Photo by Alex Wong/Getty Images)

Washington (CNN)Special counsel Robert Mueller had a busy summer, the highlight being the investigation's first jury trial, brought against former Trump campaign chairman Paul Manafort. But despite calls for him to end the probe by the beginning of September, Mueller's team is on track for an even busier fall.

Here's a breakdown of what to expect from the ongoing criminal investigation:

Another major Manafort trial

The dust has now settled in Alexandria, Virginia, where a jury convicted Manafort of eight counts of financial fraud. But another Manafort trial is looming across the Potomac River in Washington.
    That trial is scheduled to begin on September 17 and is expected to last longer than the Virginia case, which created a month-long stream of damaging headlines for Trump's campaign chairman.
    In the Washington case, Manafort is accused of illegally lobbying for the government of Ukraine, money laundering, and allegedly tampering with potential witnesses. Has pleaded not guilty to the charges.
    It's unlikely that Manafort's Trump campaign role will factor into the trial -- the alleged crimes predate his work for Trump. But some unsavory details could surface, as they did during the Virginia case.

    Sentencing for Papadopoulos, Cohen

    Trump campaign adviser George Papadopoulos, the lower-level staffer dubbed by Trump allies as a "coffee boy," will soon learn his fate and whether he will go to prison for lying to investigators.
    His sentencing is scheduled for September 7. Prosecutors want him to serve six months in prison.
    Meanwhile, federal prosecutors in New York, working on a referral from Mueller, secured a guilty plea Tuesday from Trump's longtime attorney and fixer Michael Cohen. He pleaded guilty to eight counts, including violating campaign finance law when he paid adult film star Stormy Daniels to stay quiet about her alleged affair with Trump. In open court, Cohen implied Trump directed him to break the law.
    The biggest question swirling around Cohen is whether he will provide Mueller with incriminating information about the president. Cohen's lawyer Lanny Davis hasn't been shy about dangling that possibility in the press. That will likely continue until Cohen's sentencing, slated for December 12.

    Mueller's grand jury heating up

    In addition to the trials and guilty pleas in open court, the Mueller investigation has continued in secret. Investigators have been interviewing witnesses, issuing subpoenas and seeking grand jury testimony.
      Since May, four associates of Trump ally Roger Stone were subpoenaed to testify at Mueller's grand jury, which has the power to approve an indictment against someone. Stone denies any wrongdoing and says Mueller is running a sham investigation, but also says he's expecting that he could be charged.
      Will the steady stream of witnesses continue to be hauled before the grand jury? It's nearly impossible to know. But if this continues into fall, it's a clear sign that the investigation is not wrapping up.